Camera Integrated with Direct and Indirect Flash Units

ABSTRACT

A compact camera with a compact camera body integrated with a lens, a direct flash module and an indirect flash module. The direct flash unit includes a flash light emission window arranged to project direct illumination in a first direction toward an object to be photographed. The indirect flash unit includes an indirect flash light emission window arranged to project indirect bounce illumination in a second direction off of an indirect reflecting surface to the object. The camera also has a controller that receives a first signal containing information from a first light sensor connected to the direct flash unit, and a second signal containing information from a second light sensor connected to the indirect flash unit. In response to the received first and second signals, the controller selectively adjusts the amount of flash illumination projected from the direct and indirect flash units.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.12/070,009 filed on Feb. 14, 2008, entitled “Camera Integrated withDirect and Indirect Flash Units”, the entirety of which is incorporatedherein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a photography camera thatprovides direct and indirect flash capabilities, and more particularlyto an automated compact camera including a built-in, indirect, flashunit that provides optimized indirect reflective illumination to theobject being photographed.

2. Description of the Related Art

Photographers continually suffer with finding a solution to diffusingthe detrimental effects caused by harsh direct flash. Intense directflash is unfavorable in that the flash light source is a harsh pointsource of light. One skilled in the art of photography understands that“bounce flash,” (i.e., flash aimed away from the object, such as at alight-colored surrounding wall and/or ceiling which is allowed to bouncetoward the object) is one solution that will soften the intenseilluminating and shadowing effects of direct flash and cast a smoothercontinuous hue of neutral lighting on the object being photographed toproduce a more pleasing photograph.

In a studio, a professional photographer can modify the lightingconditions and flash in just about every way so that it does not produceharsh light. The two most common methods for redirecting the light areto use a soft box and/or an umbrella. The soft box allows you to firethe flash directly, but through a soft-shelled box that bounces thelight around over a larger surface before being directed through atranslucent cover. The umbrella spreads the light from the flash over alarger surface area (the inside of the umbrella), but instead of beingfired directly, the flash is reversed and fires into the umbrella sothat the object being photographed is bathed in soft, indirect light.The disadvantage of these two methods is that the cumbersome externaldevices (the soft box and the umbrella) are required for enhancedlighting and must be set up and manipulated to obtain optimal lighting.Consequently, much preparation time is required and a user cannoteffectively shoot on the go or in casual settings with soft boxes andumbrellas.

There is a long felt need in the photography industry to enhance thelighting by using external indirect flash units. Including an indirectflash unit substantially equal in size to existing direct flash units incompact cameras is not practical because the indirect flash would bevastly underpowered for its intended purpose. Conventional attempts toinclude the existing indirect flash technology that would be capable ofreplicating the effective lighting of an accessory flash (e.g., xenonstrobe based) in the housing of an existing compact camera will resultin increasing the dimensions of the camera by at least 2-4 times.

By way of background, a guide number (GN) is used to indicate how muchlight a flash will produce when it goes off. As the GN gets higher, theintensity of the light increases as well as the distance the light cantravel. GNs are measured in feet (or meters). Many factors will affectthe physical distance the flash can cover: from outdoors to indoors, theamount your flash can light up will vary. Most GNs assume that yourdigital camera is set to ISO 100.

The GN and capacitor size are roughly proportional. Various GNs areassigned for various elements in the camera, such as for example: the GNfor current compact flash cameras and disposables is approximately 6-8;the GN for internal flashes in DSLRs is approximately 11-15; the GN forexternal hot shoe flashes is approximately 30-50; and the GN for anindirect flash in a compact camera or DSLR should be approximately 20+which would require a capacitor about the size of a C-cell battery whichis not compactly practical.

Various expensive and ingenious on-camera flash unit attachmentalternatives have been proposed, such as a hard hat with a flash mountedthereon, an external flash bracket that mounts the flash higher to pushshadows down lower, and/or attaching cumbersome indirect flash units(such as shown and described in U.S. Pat. No. 5,136,312 which isincorporated herein by reference in its entirety) yet none have proposedintegrating an adjustable bounce flash unit in a compact manner directlyinto a camera that can be easily manipulated by a lay consumer.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a system and method fora compact camera integrated with direct and indirect flash capabilities.The automated compact camera (such as a Point and Shoot or DigitalSingle Lens Reflex (SLR) includes built-in direct and indirect flashunits providing optimized direct and indirect reflective illumination tothe object being photographed.

The direct flash unit includes a flash light emission window arranged toproject direct illumination in a first direction toward an object to bephotographed. The indirect flash unit includes another indirect flashlight emission window arranged to project indirect bounce illuminationin a second direction off of an indirect reflecting surface to theobject.

This invention also relates to the integration of sensors and softwarerelated to the flash settings, exposure settings and other features ofthe camera. The camera includes a controller that receives a firstsignal containing information from a first light or distance sensorconnected to the direct flash unit, and a second signal containinginformation from a second light or distance sensor connected to theindirect flash unit. In response to the received first and secondsignals, the controller selectively adjusts the amount of flashillumination projected from the direct and indirect flash units.Likewise, in response to the information received from the first andsecond signals, the indirect flash unit can be angularly adjusted toproject flash lighting in an optimal direction to cast the best light onthe object being photographed.

It is a further object of this invention to solve the problem ofintegrating indirect flash technology directly into a camera whilepreserving the compact miniature nature of the photographic device. In apreferred embodiment the invention incorporates the use of flash powerlight emitting diodes (LED) although the invention could employconventional xenon based flash technology.

Power LEDs are comparable in illumination to a xenon flash, yet superiorin numerous other facets. The LED is easier to design and is moreflexible in its operating mode. The LED is small in physical size, andholds a longer battery charge. Likewise, the drive requirements forpower LEDs do not require high peak voltages like xenon tubes require,thus, the LED driver is substantially more compact and requires fewercomponents of smaller physical size.

According to another aspect of the present invention the improved cameraprovides a method of providing flash illumination for a cameraintegrated with a direct flash unit and an indirect flash unit. Themethod includes sensing an amount of light reflected from a reflectingsurface adjacent to the camera and based on the received information, anappropriate power level is determined and sent to an indirect flashunit. The indirect flash unit is then instructed to project a flashtoward the reflecting surface according to the determined power level.Likewise, an amount of light reflected from an object to be photographedis also received, and appropriate power level is determined and sent tothe direct flash unit. Based on the direct flash power determination,the direct flash unit is instructed to project a predetermined amount offlash toward the object.

According to yet another aspect of the present invention the improvedcamera provides an orientation sensor and control feature so that theindirect flash unit moves to accommodate the orientation of the camera.In particular, when the user changes an orientation of the camera (e.g.,from horizontal to vertical), the indirect flash is modified from a topflash to a side flash being used as the indirect flash. The altering ofa preferred indirect flash unit may be determined mechanically orelectronically.

These and other objects, features, and/or advantages may accrue fromvarious aspects of embodiments of the present invention, as described inmore detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

Various exemplary embodiments of this invention will be described indetail, wherein like reference numerals refer to identical or similarcomponents or steps, with reference to the following figures, wherein:

FIG. 1 depicts an exemplary view of a camera integrated with a directflash unit and an indirect flash unit in accordance with this invention.

FIG. 2 depicts another exemplary view of a camera integrated with adirect flash unit and a pair of indirect flash units in accordance withthis invention.

FIG. 3 illustrates a diagrammatic view illustrating a system and methodfor providing illumination flash for image capture according to anexemplary embodiment of the camera in the invention.

FIGS. 4 and 5 depict an exemplary illustration of the adjustmentmechanism of the camera system adjusting the flash light units from afirst position to a second position according to this invention.

FIG. 6 illustrates an exemplary control circuit for the camera accordingto this invention.

FIG. 7 depicts a diagrammatic view illustrating a camera integrated witha flash unit having flash beam splitting characteristic which divides asingle flash into predetermined proportions in a first direct flash pathand into a second indirect flash path in accordance with this invention.

FIG. 8 illustrates an exemplary control routine process that takes placein accordance with this invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Particular embodiments of the present invention will now be described ingreater detail with reference to the figures. Like reference numeralsapply to similar parts throughout the several views.

This invention overcomes the conventional problems described above byproviding an automated compact camera such as a point-and-shoot or DSLRincluding a built-in, indirect, flash unit that provides optimizedindirect reflective illumination to the object being photographed. Ingeneral, in a first embodiment, the camera will utilize a two-flashsystem. The camera provides a conventional single direct flash cameraand adds at least one set of flash components. The at least oneadditional sets of flash components would be embodied as an indirectflash unit.

The indirect flash unit may be pointed in a direction which would causethe projected light to bounce off of a wall, a ceiling or a surfaceprior to illuminating the object. The direct flash unit would triggerthe indirect flash every time the main direct flash fires. The f-stopmay be reduced slightly to account for entry of additional light.

The advantage of this configuration over direct-only flash producedphotos is a significant improvement. However, the disadvantage ofemploying conventional circuitry for use with a conventional xenon flashunit is that the capacitor embedded within the circuitry of aconventional camera is too small to handle much more than the directxenon flash unit. Conventional capacitors lack power and cannot providesubstantial indirect flash illumination as well as direct flash withoutcompromising the size of the compact camera. The capacitor alone wouldhave to be increased in size to roughly that of an AA to C size batterythereby yielding (the once compact camera) to a cumbersome non-compactdesign.

FIG. 1, in more detail, illustrates an exemplary two-flash compactcamera system 10 for capturing images in accordance with this invention.The camera 5 is comprised of a housing 12 including a front side 13, arear side 14, a top side 15, a bottom side 16, a left side 17, and aright side 18. As shown, a view finder 9 and a telescopic lens 11 aredisposed on the front side 13 of the camera 5. An image trigger button 8is disposed on the top side 15 of the camera 5.

According to yet another aspect of this invention, the camera system 10may be constructed as a three-flash compact camera system 10. In brief,a once existing digital camera (e.g., a point and shoot, or SLR) may beintegrated with one or more flash units. The flash units may be orientedin a variety of different directions, including but not limited to beingpointed sideways as shown and discussed in combination with FIG. 2.

FIG. 2 depicts a three-flash compact camera system 10. The various flashunits 20 a, 21 a, 22 a are disposed within compartments below the flashlight emission windows 20, 21, 22 on the camera 5. In particular, afirst direct flash light emission window 20 is disposed on the frontside 13 of the camera 5. The direct flash light emission window 20 isarranged to project direct illumination in a first direction toward anobject to be photographed.

Referring to FIG. 1, the various indirect flash light units 21 a, 22 bare housed within respective indirect flash light windows 21, 22. Afirst indirect flash light emission window 21 is shown disposed on thetop side 15 of the camera 5. A second indirect flash light emissionwindow 22 is also depicted on the right side 18 of the camera 5. Theindirect flash light emission windows 21, 22 are arranged to projectindirect bounce illumination in a direction different from the directionof the direct flash light unit 20 a. It is to be understood that theflash units and/or direct or indirect flash light emission windows maybe positioned at a variety of different positions on the camera 5. Theflash units 20 a, 21 a, 22 a utilized as part of this invention may beselected from an assortment of available illumination sources(individually or separately), including but not limited to xenon flash,light emitting diode (LED) or other suitable compact light source.

Another aspect of the present invention is to provide a position sensor60 (as shown in FIGS. 4-5). The position sensor 60 (and/orvertical/horizontal sensor) is provided to determine the orientation(such as from a horizontal to a vertical position) of the camera 5. Assuch, when the orientation is changed, the side indirect flash unit 22 anow becomes the preferred indirect top flash unit. Accordingly, only oneindirect flash unit may be preferred for use when the camera 5 capturesthe image. In the alternative, it is possible to use more than one ofthe indirect flash units 21 a, 22 a simultaneously.

Once the orientation of the camera 5 is determined, the position sensor60 returns that information in the form of a signal to a controller 35(as will be described in more detail later). Various types of positionsensors (i.e., vertical/horizontal measuring sensors) may beincorporated (such as an accelerometer or a gyroscope) to determine theorientation of the camera 5 relative to the ground.

For example, the accelerometer (as the position sensor 60) can sense anddetermine the angular displacement using the direction of gravity as avertical reference. Likewise, the position sensor 60 may determine andselectively identify which of the various indirect flash units 21 a, 22a should be used to direct the flash illumination towards a particularreflecting surface, such as the ceiling. Based on the determination madeby the controller 35 (e.g., in response to other unknown reflectivityobjects such as a wall, other objects and/or bystanders), the otherindirect flash units may be turned off. The altering of which indirectflash unit to be used may be determined mechanically (for example by theuser) or electronically (for example by the controller 35).

According to yet another aspect of this invention, conventional xenondirect flash units may be replaced by at least one or more LED flashunits capable of illuminating comparable luster within the colorspectrum as with conventional xenon flash technology.

The advantage of employing LEDs, as opposed to xenon flash tubes, isthat large high voltage capacitors and bulky circuit components are notrequired with LEDs thereby fostering miniaturization of compact cameras.Likewise, LEDs can be implemented with fewer components and an overallsmaller physical size. Unlike xenon flash units, LED drivers are muchsmaller and can be driven directly by integrated circuits (IC)containing high current pulse drivers. By way of comparison, a completedriver for an LED flash can occupy less than 10 percent of the volume ofa comparable xenon driver.

In the alternative, LEDs may be driven by lower voltage super-capacitorcircuits that are significantly smaller than conventional high voltagephotoflash capacitors, such as for example the GS-line ofsupercapacitors from the Australian based company CAP-XX® which resolvethe power and performance limitations of conventional batteries. Thedrive requirements for power LEDs do not require high peak voltages likexenon tubes require. It is important to note that a capacitor isoptional for an LED flash, whereas a xenon flash cannot operate withouta capacitor.

LEDs are significantly smaller and slimmer than xenon systems allowingfor smaller camera designs. LEDs also require less power and will leadto lower overall system costs. Unlike xenon solutions, power LEDs offerenhanced variable operating modes such as torch, flash and high speedrepeated flash, thereby creating opportunities for differentiation andgreater, more valuable, functionality.

An LED easily matches the performance of xenon technology and does so ina much more compact manner and smaller volume. Unlike cumbersome xenonflash tubes which have lower life spans and demand higher power sources,LEDs sustain their flash life much longer and at a significantly reducedpower. Furthermore, LEDs do not require constant recharge after eachdischarge. For example, a typical xenon flash has a duration of about 1ms. On the other hand, a very bright burst of white LED light can besustained for a duration of hundreds of milliseconds which allows forextended shutter opening that is desirable by the camera operator undera variety of situations.

Electronic control of a power LED is more flexible and includes greaterflexibility in its operating modes (such as in torch mode or videomode). The prolonged operation at high light output allows night-timecamera use in video mode as well as still camera mode. Similar operatingmodes and features cannot be supported by conventional xenon technology.

Another advantage of LED technology is that the range and spread of LEDflash can be substantially optimized. For example, a lens can be used tofocus the beam at a long range thereby enabling zoom flash modes. Asshown by this invention, the LED is proven to be far more versatile andsuperior to conventional xenon flash technology in terms ofminiaturization, versatility, form factor, and time to market.

FIG. 3 illustrates a diagrammatic view illustrating a system and methodfor providing illumination flash for image capture according to anexemplary embodiment of the camera system 10 in the invention. As shown,integrated within the camera 5, there is a direct flash unit 20 a and atleast one indirect flash unit 21 a. The direct flash unit 20 a operatesto project light in a first direction 25 to illuminate an object 30directly. The indirect flash unit 21 a operates to project a flash oflight in a second direction 26 a toward an indirect reflecting surface27 to reflect the flash of light in another direction 26 b to indirectlyilluminate the object 30.

That is, the light projected from the second indirect flash unit 21 atravels along the second direction 26 a and is reflected by the indirectreflecting surface 27 in the direction 26 b toward object 30. Theindirect reflecting surface 27 may be any surface capable of reflectinglight in the environment surrounding the object 30. For example, anindirect reflecting surface 27 may be a wall and/or a ceiling in a roomand/or any other type of reflecting surface capable of bouncing lightonto the object 30 in accordance with this invention.

Unlike conventional cameras, which without an external component adaptedthereto, are not capable of providing indirect bounce light. The camerasystem 10 of this invention includes integrated within the housing ofthe camera 5, separate flash units 20 a, 21 a for direct and indirectflash illumination. In particular, a first direct flash unit 20 a mayinclude, for example, a first power LED which is arranged to project aflash light beam directly at the object 30 in a first direction 25.

The indirect flash unit 21 a may include a second power LED which isarranged to project a flash light beam 26 a upward toward the indirectreflecting surface 27. It is to be understood that the indirect flashunit 21 a may be positioned to project in any number of various indirectdirections, such as laterally toward a side wall (which will serve asthe reflecting surface) and/or against the ceiling or floor (which willalso reflect the light). The indirect flash unit 21 a projects theilluminating light at the object 30 indirectly to artificially simulatethe untreated characteristics of natural sunlight. The direct flashcould be implemented in certain situations to provide fill-in light tosoften any dark shadows thereon.

The camera system 10 includes illumination sensors 31, 32. Theillumination sensor 31 is used to detect the amount of light beingreflected from the direct flash unit 20 a or to detect the distance ofthe camera from the subject or object being photographed. Likewise, theillumination sensor 32 is used to detect the amount of light beingreflected from the indirect flash unit 21 a or to detect the distance ofthe camera from the reflecting surface 27 such as the ceiling. Theillumination sensors 31, 32 may be made from a variety of differentlight absorbing and/or sensing devices, such as an emitter-detectorsensor.

According to one exemplary embodiment, the illumination sensors 31, 32may be used to emit and detect electromagnetic radiation reflected fromthe indirect reflecting surface 27 directly to the illumination sensor32. The amount of light being reflected from the various surfaces isdetected by the illumination sensors 31, 32 and converted into a signalcontaining information about the light reflecting properties of theindirect reflecting surface 27 and the electromagnetic radiationreflected directly back from the object 30 itself. Although not depictedin FIG. 3, flash unit 22 a may also have a separate sensor for detectingreflected light, distance and generating a signal containing informationfrom the reflecting surface the indirect flash and sensor are orientedtowards.

Based on the signals received from the illumination sensors 31, 32, thecontroller 35 instructs to the flash units 20 a, 21 a, 22 a a prescribedamount of power to supply to the flash units 20 a 21 a, 22 a to optimizethe emitted LED flash light on to the object 30 to produce a favorableimage.

Various types of reflection and/or other modes for determining theamount of reflected light may be employed by this invention. Forpurposes of this exemplary embodiment, one exemplary method forcollecting light by the illumination sensors 31, 32 is to emit andcapture infrared radiation transmitted from the flash units 20 a, 21 a.Referring to FIG. 3 in particular, the illumination sensor 31 receivesinfrared radiation transmitted from the direct flash unit 20 a along apath designated 25 from which it is reflected off of the object 30.Likewise, the illumination sensor 32 receives infrared radiationtransmitted from the indirect flash unit 21 along a path designated 26 dfrom which it is reflected.

From the reflected signal information returned, the controller 35 candetermine various distances. That is, the illumination sensors 31, 32may be equipped with features to ascertain the distance between variousobjects, such as the distance between the camera 5 and an indirectreflecting surface 27 and/or a distance between the camera 5 and theobject 30 and/or any other length in accordance with this invention.Alternatively, distance sensor may be integrated within the camera asseparate devices that perform the length determining function.

Based on this distance information, the camera system 10 can optimallyadjust the amount of flash (by providing full power or by quenching theoutput of the flash illumination) that is to be required from theindirect flash unit 21 a. The input back to the illumination sensor 31can also indicate to the controller 35 that there may be no indirectreflecting surface relatively close enough to efficiently utilize theindirect flash unit 21 a.

When a negligible signal is received by the illumination sensor 32 andreturned to the controller 35, the controller 35 may instruct only thedirect flash unit 20 a to operate since the indirect flash unit 21 awould have substantially little to no effect on the captured image. Anegligible signal may be returned when, for example, an indirectreflecting surface is beyond a predetermined maximum distance which willpermit effective indirect flash. However, if the indirect reflectingsurface is at, or within, a predetermined maximum distance, the indirectflash unit 21 a may be used in response to a power level instructionsent by the controller 35.

The information contained in the signal provided by illumination sensors31, 32 is utilized by the controller 35 to provide automatic adjustmentof flash output and camera settings. In the alternative, the automaticadjustment may be overridden and manually adjusted as desired by a userwith a particular desired lighting preference.

FIG. 4 illustrates another aspect of individually, or with respect toeach other, angularly adjusting the direction of the flash units 20 a,21 a, 22 a. In accordance with this invention, the direct 20 a and/orindirect flash units 21 a, 22 a may be individually adjusted. As shownin FIGS. 3-5, the indirect flash light beam path 26 a projected byindirect flash unit 21 a is adjusted (rotated by θ₁) to flash light beampath 26 a (as shown in FIG. 5). Likewise, the flash light beam path 24 a(as shown in FIG. 3) of the direct flash unit 20 a may be adjusted(rotated by θ₂) to project the flash light unit 20 a in the adjustedflash light beam path 24 j (as shown in FIG. 5).

The angular adjustments may be automatically modified by instructionsfrom the controller 35 determined in response to various inputsreceived. The controller 35 may send instructions to an adjustmentmechanism 38 attached to the direct 20 a or indirect flash units 21 a,22 a. As shown in FIGS. 4 and 5, the adjustment mechanism 38 includes apivot mechanism attached to at least one motor (M). The instructionsfrom the controller 35 cause the adjustment mechanism 38 to mechanicallyrotate the flash unit 21 a within its compartment 39 an angle θ so as tooptimally align a projection direction of the illuminating flash beamtoward the object 30.

For example and as shown in FIG. 3, if the reflected light captured bythe illumination sensor 31 indicates that the object 30 a is close tothe camera 5, the indirect flash unit 21 a may be angled at a steepangle (as shown by paths 26 e and 26 f in FIG. 3) to optimize the amountof light reflected onto the object 30 a. However, if the reflected lightcaptured by the illumination sensor 32 indicates that the object 30 b isfurther from the camera 5, the angle of projection of the indirect flashunit 21 a may be lowered (as shown by paths 26 g and 26 h in FIG. 3) tooptimize the amount of light reflected onto the object 30 b. Further,the illumination sensor 32 will also determine the distance andreflectivity characteristics of the ceiling or reflective surface andthe controller 35 can adjust the power to the light in combination withthe angle or projection.

As discussed previously, the position sensor 60 is provided to determinethe orientation (such as from a horizontal to a vertical position) ofthe camera 5. As the angle of the camera 5 changes from the horizontalto the vertical position, the side indirect flash unit 22 a becomesreoriented by the movement of the camera 5 to the preferred indirect topflash unit in the position the indirect flash unit 21 a previously waspositioned. When more than one indirect flash unit is available for use,one of the indirect flash units may be preferred for use when the camera5 captures the image. Based on various factors, including but notlimited to, a determination made by the controller 35 (e.g., in responseto other unknown reflectivity objects such as a wall, other objectsand/or bystanders), the other indirect flash unit(s) may be turned offso that only one indirect flash unit is used. The determination to useone indirect flash unit over the other may be determined mechanically orelectronically.

According to this invention, another advantage of aiming the directflash at a slight off angle is so that the off-angle direct flash mayreduce red-eye. This use may be desired, for example, when used inconjunction with indirect lighting.

FIG. 6 illustrates a control circuit diagram for the camera system 10. Abattery source 42 provides power to the various components connected inthe control circuit. A controller 35 is electrically connected withinthe circuit to a direct flash unit circuit 121. The controller 35 isalso electrically connected with at least one indirect flash unitcircuit 122. The battery source 42 may likely be tied into the powersource that supplies the various camera features and functionality.

The illumination sensors 31, 32 are depicted attached to the controller35 within the control circuit. The illumination sensor 31 is depictedelectrically connected to the direct flash unit circuit 121, and theillumination sensor 32 is shown electrically connected to the indirectflash unit circuit 122. As mentioned previously, the illuminationsensors 31, 32 may incorporate an emitter-detector sensor in which anambient infrared radiation detector is provided within the camera system10 as a point of reference for the controller 35 in evaluating andmaking a determination as to how much power should be sent to the directand indirect flash units 20 a, 21 a, 22 a during operation and/orwhether to permit, quench and/or adjust the flash operation of the flashunits 20 a, 21 a, 22 a. As also mentioned previously, the illuminationsensors 31, 32 may be used to collect various types of information,including but not limited to, the distance of the object 30 from thecamera 5 and/or information regarding exposure settings (aperture andshutter speed).

The various components in the circuit diagram of the camera system 10are electrically connected and designed to send and receive signalinformation to and from the controller 35 via various bus lines showngenerally as 36. The controller 35 centrally coordinates the receipt ofthe information and instructions to the various components of the camerasystem. Various types of information may be received by the controller35 from various inputs into the control circuit and will be discussed inmore detail later.

A quenching flash circuit 41 is shown provided within the controlcircuit to regulate the power of the flash from the direct and indirectflash units 20 a, 21 a, 22 a. That is, the power of a flash is regulatedby quenching the flash before the capacitors are fully discharged.Although the phraseology for quenching is described, it is to beunderstood within this invention to allow for the halt of the flash midexposure through, for example via a solid state circuit in the eventthat light sensors observe sufficient light has been achieved. Haltingthe flash may be accomplished by solid state circuitry (or other) thathas the ability to open a circuit and halt a flash, whether manually orautomatically. At least one source of quenching signals may utilize thedistance information gathered from distance sensors. Other sources mayuse light coming from the scene in which the object 30 is located, allof which is well known to those skilled in the art.

Basic descriptions for trigger and quenching circuits for direct andindirect flash tubes (such as the interaction of a battery connected toa main capacitor and various resistors and SCR's connected in a triggercircuit) for an external attachment for a camera are known and are notthe subject of this application and can be found in U.S. Pat. No.5,136,312 and U.S. Pat. No. 4,384,238, the disclosures of which arehereby incorporated by reference.

Referring back to the controller 35, as with conventional cameras, thecontroller 35 receives various types of information as data signalinputs, such as for example: distance information from an auto-focusmodule, film speed data input, ambient light level from aphoto-detector, ceiling or indirect reflecting surface detection, flashspecification information yielding exposure information, informationfrom a user interface (such as no flash, rapid recycle or no indirectflash) and various other types of information.

The controller 35 provides various control signal instructions, such asshutter speed, an F-number, indirect flash parameters, direct flashparameters, and various other control signals. According to thisinvention, the controller 35 can also instruct the flash units, such asthe indirect flash units 21 a, 22 a how to orient the angle ofprojection based on the various inputs received to optimize the lightaround the object 30 being photographed.

It should be noted that the controller 35 may be preferably implementedas a central processor section having overall, system-level control, toperforming various computations, functions and other processes relatedto the camera system 10. The various components in the control circuitassociated with the processor 35 can be implemented as a singlemicroprocessor circuit or a plurality of separate dedicated orprogrammable integrated or other electronic circuits or devices, e.g.,hardwired electronic or logic circuits such as discrete element circuitsor programmable logic devices. The control circuit may include othercircuitry or components common in camera photography, such as memorydevices, etc., to affect desired control and/or input/output functionsfrom various input/output interfaces. The camera system 10 may includemore than one controller for the various electronic components inaccordance with this invention.

Programmable memory may be provided to receive and store the variousdata information and can also store one or more computer readablecontrol routines used by the camera system 10. The memory can beimplemented using any appropriate combination of alterable, volatile ornon-volatile memory or non-alterable, or fixed, memory. The alterablememory, whether volatile or non-volatile, can be implemented using anyone or more of static or dynamic RAM, floppy disk and disk drive,writable or re-writable optical disk and disk drive, hard drive, flashmemory or the like. Similarly, the non-alterable or fixed memory can beimplemented using any one or more of ROM, PROM, EPROM, EEPROM, anoptical ROM disk, such as CD-ROM or DVD-ROM disk, and disk drive or thelike.

FIG. 7 illustrates another exemplary embodiment in which the camerasystem 10 includes a single flash unit source and a beam splitter 40that separates the flash light illumination into a direct flash beam andan indirect flash beam. Although depicted a distance away from the flashunit 20 a, the beam splitter 40 is intended to be disposed within thecamera 5. Alternatively, the beam splitter 40 may be implemented throughthe use of a reflective and diffusing surface such as a bounce cardwhich is commonly used by professional photographers. The bounce card isa small surface which deflects light from the indirectly aimed flashunit towards the subject. The surface may be integral to the camera orconstructed as an add on attachment. That is, the beam-splitter 40deflects a portion of the flash LED light towards an indirect reflectingsurface 27 and the remaining light is emitted along an axis defineddirectly between the lens of the camera 5 and the object 30.

In brief, if a suitable indirect reflecting surface 27 is not detected,the use of the beam-splitter 40 is omitted and all of the projectedflash light is directed along the axis defined directly between the lensof the camera 5 and the object 30. In use, infrared radiation is emittedfrom an IR beam source included in the illumination sensor system 32along a path designated 26 a to surface 27. The IR beam source isreflected along a path back to illumination sensor 32. Information aboutthe indirect reflecting surface 27 is embedded in the signal andprovided back to the illumination sensor 32. If the surface 27 is notpresent, or is located beyond a predetermined distance, a beam splitter40 is not employed and the direct flash light beam 25 is not separatedand all of the flash light is illuminated directly on the object 30.

However, if the signal indicates the presence of surface 27 within apredetermined distance, the controller 35 adjusts a beam splitter 40 tofunctionally separate the direct flash unit 20 a to deflect a portion ofthe incoming flash light 25 along a first direct path 25 a and theremaining portion of the flash light along a second indirect path 25 b.The flash light for the second indirect path 25 b may be optimally usedwith a larger lens opening than that used for the direct flash modewhere an equivalent flash range is desired to account for the longerpath length that the indirect flash light beam has to travel and lightloss associated with the bounced light.

The schematic diagram and the control circuit function shown in FIG. 7are similar to the schematic diagram and the control circuit describedabove with the exception that a single direct flash unit 20 a projects asingle flash beam of light 25 that is separated by a beam splitter 40into a first projected direct flash light beam 25 a and a secondindirect flash light beam 25 b of indirect flash illumination that isreflected off of the indirect reflected surface 27.

In particular, when the beam splitter 40 is used, the incoming singleflash beam of light 25 is split and projected, in part, in a firstdirection 25 a toward the indirect reflecting surface 27 and reflectedoff back to the object 30. The second part of the incoming single flashbeam of light 25 is further split in a direct path 25 a in a seconddirection to directly illuminate the object 30.

The beam splitter 40 may be optimally adjusted by an electromechanicalactuator 41 that operates to pivot the angle of the beam splitter 40. Byangling the beam splitter 40, the proportionate amount of illuminatedlight split can be varied thereby modifying and splitting the incomingflash beam of light 25 as desired into a first direct flash beam oflight 25 a directed at the object 30 and a second indirect flash beam oflight 25 b, 25 c indirectly hitting the object 30.

When the beam splitter 40 is not used, such as where indirect light issubstantially ineffective, the beam splitter 40 will be predisposed in afirst position to allow all of the flash light illumination to projectdirectly onto the object 30. Although described as a beam splitter 40,the flash illumination device may be composed from any number of varyingdesigns, such as a partially silvered mirror and/or a separator lens.

FIG. 8, illustrates an exemplary control routine process that takesplace in accordance with this invention.

In Step S1, the control routine determines if the camera is being usedin a manual or automatic mode of operation. If a manual mode ofoperation is being used, the routine proceeds to Step S2. However, ifthe automatic mode is selected, then the routine proceeds to Step S3.

In Step S2, manual override of settings may be selected. Manual overridemay be selected from a menu in the camera and/or may be actuated inresponse to a user manipulating the features on the camera, and/or someother overriding procedure. The control routine is highly adaptive andmay include at least the following basic features. First, the user willbe able to override the software (such as for example: turning the flashon/off, and/or causing the indirect/direct flash units to operatetogether or independently). The control routine is adapted to manipulatethe flash power in response to detecting and analyzing the light alreadypresent and the various features and parameters discussed in more detailbelow.

Alternatively, in Step S3, manual override of setting is not selectedand an automatic or auto-focus mode may be selected so that the camerasetting may be optimally configured by an internal control program basedon the various parameters described above. In operation, the shuttertrigger switch (or image trigger button) on the camera is depressed andactivates the automatic control routine according to this invention.

In the automatic mode, the control routine of this invention receivesvarious bits of information and analyzes the information the varioustypes of information received, such as for example: object andreflective surface distances (e.g., upward and side distances in theenvironment), light metering data, and vertical/horizontal positioningof the camera to determine how much light should be emitted and fromwhich of various direct and indirect flash units.

The automatic flash mode selects an appropriate camera lens aperture andshutter speed based on a distance determined between the camera and theobject and a determined flash output. The automatic flash mode willselect a suitable aperture and shutter speed selection for the directflash light mode. If an indirect reflective surface is detected havingsuitable reflective properties to enhance the object being photographed,an indirect and direct mode pair may be selected. In the case where beamsplitting may be employed, larger lens openings may be suitably selectedto offset the light losses and longer path length. The desired objectiveis to obtain uniform exposure of the object. In Step S2, when theshutter release button is depressed, distance and light sensors (StepS4) are initiated.

In Step S4, the distance sensors determine the various distances betweenthe parameters surrounding the object to be photographed in a variety ofdirections (upward, sideways, bottom, forward)—as well as the distancebetween the camera and the object. The various distance informationcollected will establish a point of reference between the object and thecamera and the surrounding environment.

The control routine can adapt to the varied distance of the object. Thegreater the distance the indirect bounce surface is located from thecamera and/or the object, the more power the indirect flash will need tobe charged or driven at when using non-capacitor circuit to illuminatethe object being photographed. That is, the greater the distance, thestronger the indirect flash unit must illuminate the flash. Similarly,the direct flash unit will also increase its illumination of its flashas the distance of the object from the camera is increased.

In the alternative, sensors for determining distance and reflectivityfor indirect flashes may be omitted and instead a low power pre-flashmay be performed for each indirect flash independently and measure thelight reaching the subject with existing light meters and feedinformation into flash/exposure software prior to the shutter opening.That is, rather than utilizing distance/light/reflectivity sensors onindirect light sources, the following alternative method can be employedto determine the power output of each indirect light source. Assumingthe camera is in automatic mode, after the user presses the shutterrelease button, each flash unit source (direct and indirect)sequentially fires at low power. The camera's existing light sensor(s)(the one that is used for determining exposure) observes the amount oflight that has reached the subject of the photograph from each of theflashes. This process may take many milliseconds. The camera then usesthe sensor input along with other data received by the controller todetermine the power output of each flash during the actual imagecapture. The shutter is then opened and the multiple flashes fire forimage capture. The shutter is closed and the image is processed by thecamera. The user presses the shutter release button once during thisprocess and user may experience some shutter lag. Alternatively, thesensing process can occur when the user presses and holds the shutterrelease button at a mid-position allowing the user to exactly time theshutter release when he completely presses the shutter release button(this is a common feature of cameras to allow for pre-shutter releasesensing of focus and exposure).

Circuitry will be included to allow a quench or immediate halt of thelight emission of each flash unit if the control routine sends aninstruction to the flash units. According to this alternative, flashbracketing could be employed by adjusting the emphasis of each of apredetermined number of flashes (e.g., three flashes) as well as theintensity of each in a sequence of photographs. The advantage of thisstep is that the nature of the LED flashes allows for numerous shotswithout the need for capacitor recharging. In the alternative to havingthree fixed LED flashes, a top flash may flip out at a predeterminedangle, (e.g., approximately 90 degrees) to serve as in indirect sideflash in response to the vertical/horizontal sensor commands. Theroutine then proceeds to Step S5.

In Step S5, a light meter determines the available and/or required lightfor proper exposure. The light meter may be comprised of any number oflight sensors, such as an ambient light level sensor. In each of thevarious directions that the light meter takes samples, the lightreceived is compared against the light transmitted to determine anoptimal amount of light that is to be transmitted toward the object. Theroutine proceeds to Step S6.

In Step S6, a vertical/horizontal sensor is activated to determine thecamera orientation. Once the orientation has been determined, thevertical/horizontal sensor returns that information in the form of asignal to a central controller. Various types of vertical/horizontalmeasuring sensors may be incorporated (such as an accelerometer or agyroscope) to determine the orientation of the camera relative to theground. The accelerometer can sense and determine the angulardisplacement using the direction of gravity for a vertical reference.Likewise, the vertical/horizon sensor may determine and selectivelyidentify which indirect flash unit is directed towards a particularreflecting surface, such as the ceiling and may as a result shut downthe other indirect flash units (in response to other unknownreflectivity objects such as a wall, other objects and/or bystanders).The routine proceeds to Step S7.

In Step S7, based on at least some of the information collected by thedistance sensors, the light meter, and the vertical/horizontal sensor,the routine can make a determination as to whether a flash is needed. Ifno flash is needed because for example, the image is being taken duringthe day and ample sunlight is available, the routine proceeds to Step S8and the picture is taken.

Otherwise, if a flash is needed, the routine proceeds to Step S9 inwhich it is further determined if an indirect flash illumination lightwould produce favorable results on the object being photographed. If theanswer is determined to be no, then the routine then proceeds to StepS10 and the photograph is taken with direct flash only.

If however, it is determined in Step S9 that indirect flash lightingwould be optimal, the routine proceeds to Step S11 in which the routinedetermines whether to use a split beam separator process of Step S12, orto employ the individual direct and indirect flash unit process asdescribed in Step S13.

In Step S12, a beam splitter that separates a single flash lightillumination into a direct flash beam and an indirect flash beam. Asdescribed earlier, a portion of the direct flash is separated towards anindirect reflecting surface and the remaining light is emitted along anaxis defined directly between the lens of the camera and the object.

In the alternative, if a suitable indirect reflecting surface is notdetected, the use of the beam-splitter is omitted and all of theprojected flash light is directed along the axis defined directlybetween the lens of the camera and the object.

In Step S13, the individual direct and indirect flash unit process isselected. The routine will now decide at what power level the direct andindirect flashes will be instructed to project optimal lighting onto theobject being photographed. The power level and/or amount of light to beoutput by each of the flash units (e.g., light emitting diodes (LEDs))is determined and that information is collected by a central controller.

In more detail, an IR is emitted from the distance sensors along a firstpath to an indirect reflecting surface. The distance sensors receivesthe infrared radiation reflected from indirect reflecting surface alonga return path and an output signal indicative of the distance betweenindirect reflecting surface and the illumination sensor is sent to thecontroller. Information about the lighting and exposure conditions isalso received.

In this exemplary embodiment, it is determined that the indirectreflecting surface is within a predetermined distance from the cameraand the indirect flash unit is actuated, or ionized, for use.

Likewise, operation of the direct flash unit is substantially similar tothe operation described above with respect to the indirect flash unit.That is, when the indirect reflecting surface determined to be within apredetermined distance of the camera, the controller may send a commandinstruction to pivot the indirect flash unit to an optimal determinedangular direction as discussed in Step S14. The instruction may bereceived by an adjustment mechanism that will reposition the projectionof the indirect flash unit to optimally project the illuminating flashlight on to the object. The controller will then instruct both thedirect flash unit and the indirect flash unit to fire simultaneously andilluminate the object.

However, if it is determined that the indirect flash unit would benegligible on the object being photographed, the indirect flash unitwill be rendered inoperable for efficiency sake. The routine will thenproceed to Step S14 and the picture will be taken with the direct flashonly.

In Step 13, when the direct and indirect flash units are charged to thepredetermined level, the flash units are ready to be discharge the flashand to produce the indirect flash in a direction at an angle suitable toreflect onto the object. The routine proceeds to Step S14.

In Step S14, based on the information collected by the various distancesand light meters, an optimum angle of indirect light projection isdetermined. The central controller instructs an adjustment mechanism toangularly adjust the axial projection of the intended flash against theindirect surface to optimally reflect flash lighting on the object tocast favorable light onto the object when the shutter opens to capturethe image of the object.

In Step S15, the focal distance of the camera lens is set by anauto-focus motor according to the distance determined between the cameraand the object. Alternatively, focal distance can be determined by athrough-the-lens (TTL) process that optimizes edge contrast of the imageand is a method currently employed within the industry. In anotherexemplary alternative, a motorized lens or mirror may be attached toeach flash unit to adjust the focal distance or angle based on thebounce distance required to project on the object. It is to beunderstood that multiple focal length flashes may be embodied in eachflash unit. Alternatively, numerous LEDs may be positioned on, forexample, a ¼ sphere (like the eye of a fly) to serve as an array for thedirect and indirect flashes. In each flash unit, varying color spectrumLEDs may be added to allow for creative lighting effects. The routineproceeds to Step S16.

In Step S16, the aperture and shutter speed of the camera are determinedin response to the various information collected and signaled to thecentral controller. The control routine may operate in response to avariety of different types of flash/exposure software. The routineproceeds to Step S17.

In Step 17, the shutter opens and light from the light emitting diodes(LED) flash units is projected onto the object and optimal lighting isreceived by the film/digital sensor to impress an image of the object.The routine monitors the exposure light of the image while the shutteris open to capture the image. The shutter remains open for apredetermined duration of time. Once it is determined that properexposure has been achieved prior to shutter close, all flashes arequenched. The routine proceeds to Step S18.

In Step S18, the quench command signal appears to inhibit the flash. Thequenching command regulates the power of the flash from the direct andindirect flash units. It is within the scope of this invention to allowfor the halt of the flash mid exposure through, e.g., via a solid statecircuit in the event that light sensors observe sufficient light hasbeen achieved. The halting of the flash may occur manually orautomatically. The routine then proceeds to Step S19.

In Step S19, color correction and noise reduction may be applied to thecaptured image of the object. Conventional techniques and software maybe applied. The routine proceeds to Step S20.

In Step S20, the data is stored (and/or film is advanced) to media andphoto is complete. The routine proceeds to Step S21 and the processends.

Although various steps are described above according to the exemplarymethod of this invention, it is to be understood that some of the stepsdescribed above may be omitted, and others may be added withoutdeparting from the scope of this invention.

Various alternatives are possible in accordance with this invention. Forexample, the LEDs may be constructed as removable indirect hot shoeflash attachment that is compact and not powered by its own battery. Theadvantage of this reduced size of the LED flash attachment is that theattachment can remain attached to the hot shoe in a compact manner. Thismay involve redesign hot shoe mounts to allow power pass through fromthe main battery of the camera to the shoe-mounted flash.

The systems and methods of this indirect flash systems may be adaptedfor use with other small electronic devices capable of still or videophotography, such as for example, PDAs, cell phones, computers.

It will be recognized by those skilled in the art that changes ormodifications may be made to the above described embodiment withoutdeparting from the broad inventive concepts of the invention. It isunderstood therefore that the invention is not limited to the particularembodiment which is described, but is intended to cover allmodifications and changes within the scope and spirit of the invention.

1. A camera, comprising: a camera housing; a lens to capture aphotograph; a direct flash unit within the housing including a flashlight emission window arranged to project direct illumination toward anobject to be photographed; an indirect flash unit within the housingincluding an indirect flash light emission window arranged to projectindirect bounce illumination at a surface to the object; a direct flashhalt circuit within the housing to limit the amount of light output bythe direct flash unit; and an indirect flash halt circuit within thehousing to limit the amount of light output by the indirect flash unit.2. The camera according to claim 1, wherein the direct flash haltcircuit limits the voltage to the direct flash unit.
 3. The cameraaccording to claim 1, wherein the direct flash halt circuit limits thecurrent to the direct flash unit.
 4. The camera according to claim 1,wherein the direct flash halt circuit limits the time power is providedto the direct flash unit.
 5. The camera according to claim 1, whereinthe indirect flash halt circuit limits the voltage to the indirect flashunit.
 6. The camera according to claim 1, wherein the indirect flashhalt circuit limits the current to the indirect flash unit.
 7. Thecamera according to claim 1, wherein the indirect flash halt circuitlimits the time power is provided to the indirect flash unit.
 8. Amethod of providing flash illumination for a camera with a direct flashunit within a camera housing and an indirect flash unit within thecamera housing, comprising: receiving an input to initiate the captureof an image of a subject; creating and receiving a live feed of imagedata; initiating the capture of the image; initiating a flash of thedirect flash unit; analyzing the live feed during the flash of thedirect flash unit; initiating a flash of the indirect flash unit;analyzing the live feed during the flash of the indirect flash unit;determining the amount of light to be provided by the direct flash unitand the indirect flash unit based upon the live feed analysis; andhalting the direct flash unit when sufficient direct light isdetermined; and halting the indirect flash until when sufficientindirect light is determined.
 9. The method of claim 8, wherein thehalting the direct flash unit is by limiting the voltage to the directflash unit.
 10. The method of claim 8, wherein the halting the directflash unit is by limiting the current to the direct flash unit.
 11. Themethod of claim 8, wherein the halting the direct flash unit is bylimiting the time power is supplied to the direct flash unit.
 12. Themethod of claim 8, wherein the halting the indirect flash unit is bylimiting the voltage to the indirect flash unit.
 13. The method of claim8, wherein the halting the indirect flash unit is by limiting thecurrent to the indirect flash unit.
 14. The method of claim 8, whereinthe halting the indirect flash unit is by limiting the time power issupplied to the indirect flash unit.
 15. A method of providing flashillumination for a camera with a direct flash unit within a camerahousing and an indirect flash unit within the camera housing,comprising: receiving an input to initiate the capture of an image of asubject; initiating a low power pre-flash of the direct flash unit;sensing the amount of light that has reached the subject from the directflash unit; initiating a low power pre-flash of the indirect flash unit;sensing the amount of light that has reached the subject from theindirect flash unity; determining the amount of light to be provided bythe direct flash unit and the indirect flash unit based upon the amountof sensed light; and initiating a flash of the direct flash unit andindirect flash unit at the determined light levels while capturing theimage.
 16. A method of providing flash illumination for a camera with adirect flash unit within a camera housing and an indirect flash unitwithin the camera housing, comprising: receiving an input to initiatethe capture of an image of a subject; creating and receiving a live feedof image data initiating a pre-flash of the direct flash unit; analyzingthe live feed during the pre-flash of the direct flash unit; initiatinga pre-flash of the indirect flash unit; analyzing the live feed duringthe pre-flash of the indirect flash unit; determining the amount oflight to be provided by the direct flash unit and the indirect flashunit based upon the live feed analysis; and initiating a flash of thedirect flash unit and indirect flash unit at the determined light levelswhile capturing the image.